Transgenic and knockout mice are an integral part of the research programs of the Cancer Center. The transgenic core laboratory provides a variety of services for investigators, including microinjection of embryonic stem (ES) cells into blastocysts, microinjection of DMA into one-cell embryos, lentiviral infection of two-cell stage embryos, in-vitro fertilization (IVF), cryopreservation and re-derivation of mouse lines, providing neo-resistant mice for generating feeder cells for ES cell culture and providing inbred strains of mice.